Hygienic articles, such as feminine hygiene products (e.g., pantiliners or pads), disposable diapers, pull-ons, training pants, and adult incontinence articles, often include features such as printed images and printed text. Such features are often used for both functional and aesthetic reasons. For example, a diaper may include a popular design (e.g., a popular children's character, a team logo, and other familiar designs), to increase consumer awareness of the product.
Generally, consumers expect each hygienic article to maintain the same look and feel as one another. In most cases, hygienic articles are used sequentially by a consumer from a package, meaning that the consumer is able to more readily distinguish differences between the individual articles and notice any defects that may be present. For example, the placement of a popular design on a diaper must be consistently placed, in order to ensure that the design is fully shown (e.g., that a headless character is not shown, a team logo is not missing the name of the team's city, and other inconsistencies). These types of defects may be caused by a number of different problems in the manufacturing process. For example, a feature may be improperly placed onto a component, if the component is not positioned correctly. In another example, a printer requiring maintenance may smear a feature as it is printed onto a component.
In certain cases, it may even be desirable for hygienic articles within a package to be different. For example, a manufacturer may wish to ensure that each hygienic article in a package has a separate design. In another example, the manufacturer may wish to ensure that the package contains only a certain number of articles having the same design. In such cases, the manufacturer must ensure that each hygienic article is free from defects, as well as impose any additional limitations on how the articles are packaged.
Quality inspection of components by the naked eye is often time consuming and prone to human error. Therefore, recent efforts have been made in the field of manufacturing hygienic articles to automate some or all of the manufacturing process. However, it remains challenging and difficult to develop new techniques and systems that automatically inspect components of hygienic articles to ensure quality and consistency.